EX-99.19a-1

MFS® Intermediate High Income Fund

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders — Source of distribution

Distribution period	November-2025
Distribution amount per share	$0.01463

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

		% Breakdown	Total cumulative	% Breakdown of the total
	Current	of current	distributions for the	cumulative distributions
	distribution	distribution	fiscal year to date	for the fiscal year to date
Net Investment Income	0.01229	84%	0.11535	66%
Net Realized ST Cap Gains	0.00000	0%	0.00000	0%
Net Realized LT Cap Gains	0.00000	0%	0.00000	0%
Return of Capital or
Other Capital Source	0.00234	16%	0.05943	34%
Total (per common share)	0.01463	100%	0.17478	100%

Average annual total return (in relation to NAV) for the five years ended 10-31-2025	4.65%
Annualized current distribution rate expressed as a percentage of month end NAV as of 10-31-2025	9.49%
Cumulative total return (in relation to NAV) for the fiscal year through 10-31-2025	8.43%
Cumulative fiscal year distributions as a percentage of NAV as of 10-31-2025	9.45%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax-reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes. If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

CIHSN-1125

MFS® Intermediate High Income Fund

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders — Source of distribution

Distribution period	October-2025
Distribution amount per share	$0.01476

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

		% Breakdown	Total cumulative	% Breakdown of the total
	Current	of current	distributions for the	cumulative distributions
	distribution	distribution	fiscal year to date	for the fiscal year to date
Net Investment Income	0.01107	75%	0.10250	64%
Net Realized ST Cap Gains	0.00000	0%	0.00000	0%
Net Realized LT Cap Gains	0.00000	0%	0.00000	0%
Return of Capital or
Other Capital Source	0.00369	25%	0.05765	36%
Total (per common share)	0.01476	100%	0.16015	100%

Average annual total return (in relation to NAV) for the five years ended 9-30-2025	4.75%
Annualized current distribution rate expressed as a percentage of month end NAV as of 9-30-2025	9.52%
Cumulative total return (in relation to NAV) for the fiscal year through 9-30-2025	8.09%
Cumulative fiscal year distributions as a percentage of NAV as of 9-30-2025	8.61%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax-reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes. If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

CIHSN-1025

MFS® Intermediate High Income Fund

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders — Source of distribution

Distribution period	September-2025
Distribution amount per share	$0.01466

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

		% Breakdown	Total cumulative	% Breakdown of the total
	Current	of current	distributions for the	cumulative distributions
	distribution	distribution	fiscal year to date	for the fiscal year to date
Net Investment Income	0.01070	73%	0.09160	63%
Net Realized ST Cap Gains	0.00000	0%	0.00000	0%
Net Realized LT Cap Gains	0.00000	0%	0.00000	0%
Return of Capital or
Other Capital Source	0.00396	27%	0.05379	37%
Total (per common share)	0.01466	100%	0.14539	100%

Average annual total return (in relation to NAV) for the five years ended 8-31-2025	4.32%
Annualized current distribution rate expressed as a percentage of month end NAV as of 8-31-2025	9.46%
Cumulative total return (in relation to NAV) for the fiscal year through 8-31-2025	7.20%
Cumulative fiscal year distributions as a percentage of NAV as of 8-31-2025	7.82%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax-reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes. If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

CIHSN-0925

MFS® Intermediate High Income Fund

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders — Source of distribution

Distribution period	August-2025
Distribution amount per share	$0.01458

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

		% Breakdown	Total cumulative	% Breakdown of the total
	Current	of current	distributions for the	cumulative distributions
	distribution	distribution	fiscal year to date	for the fiscal year to date
Net Investment Income	0.01123	77%	0.08105	62%
Net Realized ST Cap Gains	0.00000	0%	0.00000	0%
Net Realized LT Cap Gains	0.00000	0%	0.00000	0%
Return of Capital or
Other Capital Source	0.00335	23%	0.04968	38%
Total (per common share)	0.01458	100%	0.13073	100%

Average annual total return (in relation to NAV) for the five years ended 7-31-2025	4.00%
Annualized current distribution rate expressed as a percentage of month end NAV as of 7-31-2025	9.51%
Cumulative total return (in relation to NAV) for the fiscal year through 7-31-2025	5.18%
Cumulative fiscal year distributions as a percentage of NAV as of 7-31-2025	7.10%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax-reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes. If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

CIHSN-0825

MFS® Intermediate High Income Fund

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders — Source of distribution

Distribution period	July-2025
Distribution amount per share	$0.01448

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

		% Breakdown	Total cumulative	% Breakdown of the total
	Current	of current	distributions for the	cumulative distributions
	distribution	distribution	fiscal year to date	for the fiscal year to date
Net Investment Income	0.00652	45%	0.06853	59%
Net Realized ST Cap Gains	0.00000	0%	0.00000	0%
Net Realized LT Cap Gains	0.00000	0%	0.00000	0%
Return of Capital or
Other Capital Source	0.00796	55%	0.04762	41%
Total (per common share)	0.01448	100%	0.11615	100%

Average annual total return (in relation to NAV) for the five years ended 6-30-2025	5.26%
Annualized current distribution rate expressed as a percentage of month end NAV as of 6-30-2025	9.39%
Cumulative total return (in relation to NAV) for the fiscal year through 6-30-2025	4.89%
Cumulative fiscal year distributions as a percentage of NAV as of 6-30-2025	6.28%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax-reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes. If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

CIHSN-0725

MFS® Intermediate High Income Fund

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders — Source of distribution

Distribution period	June-2025
Distribution amount per share	$0.01432

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

		% Breakdown	Total cumulative	% Breakdown of the total
	Current	of current	distributions for the	cumulative distributions
	distribution	distribution	fiscal year to date	for the fiscal year to date
Net Investment Income	0.00931	65%	0.06304	62%
Net Realized ST Cap Gains	0.00000	0%	0.00000	0%
Net Realized LT Cap Gains	0.00000	0%	0.00000	0%
Return of Capital or
Other Capital Source	0.00501	35%	0.03863	38%
Total (per common share)	0.01432	100%	0.10167	100%

Average annual total return (in relation to NAV) for the five years ended 5-31-2025	4.83%
Annualized current distribution rate expressed as a percentage of month end NAV as of 5-31-2025	9.44%
Cumulative total return (in relation to NAV) for the fiscal year through 5-31-2025	2.35%
Cumulative fiscal year distributions as a percentage of NAV as of 5-31-2025	5.59%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax-reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes. If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

CIHSN-0625