Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2019


	2020		2019		Recovery Period
	(In Thousands)
Regulatory Assets
Current:
Undercollections of rate riders	$	31,569	$	22,216	Approximately 1 year(1)
Costs being recovered through basic rates and charges	13,861		15,182		Approximately 1 year(1)
Total current regulatory assets	45,430		37,398
Long-term:
Unrecognized pension and other
postretirement benefit plan costs	149,374		176,646		Various (2)

Deferred MISO costs	61,267		74,660		Through 2026(1)
Unamortized Petersburg Unit 4 carrying
charges and certain other costs	5,975		7,030		Through 2026(1)(3)
Unamortized reacquisition premium on debt	17,018		18,330		Over remaining life of debt
Environmental projects	74,637		78,021		Through 2046(1)(3)
COVID-19	6,391		—		To be determined
TDSIC projects	2,747		—		36.3 years(1)(3)
Petersburg Unit 1 retirement	74,545		—		Through 2035(3)(5)
Other miscellaneous	847		927		Various (4)
Total long-term regulatory assets	392,801		355,614
Total regulatory assets	$	438,231	$	393,012
Regulatory Liabilities
Current:
Overcollections and other credits being passed
to customers through rate riders	$	29,493	$	51,790	Approximately 1 year(1)
FTRs	543		864		Approximately 1 year(1)
Total current regulatory liabilities	30,036		52,654
Long-term:
ARO and accrued asset removal costs	723,897		719,680		Not applicable
Deferred income taxes payable to customers through rates	112,957		122,156		Various
Long-term portion of credits being passed to customers
through rate riders	—		3,337		Through 2020
Other miscellaneous	2,506		1,257		To be determined
Total long-term regulatory liabilities	839,360		846,430
Total regulatory liabilities	$	869,396	$	899,084

(1)Recovered (credited) per specific rate orders

(2)IPL receives a return on its discretionary funding

(3)Recovered with a current return

(4) The majority of these costs are being recovered in basic rates and charges through 2026. For the remainder, recovery is probable, but the

timing is not yet determined.

(5) Recovered per regulatory precedent.


	2020		2019		Recovery Period
	(In Thousands)
Regulatory Assets
Current:
Undercollections of rate riders	$	31,569	$	22,216	Approximately 1 year(1)
Costs being recovered through basic rates and charges	13,861		15,182		Approximately 1 year(1)
Total current regulatory assets	45,430		37,398
Long-term:
Unrecognized pension and other
postretirement benefit plan costs	149,374		176,646		Various(2)

Deferred MISO costs	61,267		74,660		Through 2026(1)
Unamortized Petersburg Unit 4 carrying
charges and certain other costs	5,975		7,030		Through 2026(1)(3)
Unamortized reacquisition premium on debt	17,018		18,330		Over remaining life of debt
Environmental projects	74,637		78,021		Through 2046(1)(3)
COVID-19	6,391		—		To be determined
TDSIC projects	2,747		—		36.3 years(1)(3)
Petersburg Unit 1 retirement	74,545		—		Through 2035(3)(5)
Other miscellaneous	847		927		Various(4)
Total long-term regulatory assets	392,801		355,614
Total regulatory assets	$	438,231	$	393,012
Regulatory Liabilities
Current:
Overcollections and other credits being passed
to customers through rate riders	$	29,493	$	51,790	Approximately 1 year(1)
FTRs	543		864		Approximately 1 year(1)
Total current regulatory liabilities	30,036		52,654
Long-term:
ARO and accrued asset removal costs	723,897		719,680		Not applicable
Deferred income taxes payable to customers through rates	112,957		122,156		Various
Long-term portion of credits being passed to customers
through rate riders	—		3,337		Through 2020
Other miscellaneous	2,506		1,257		To be determined
Total long-term regulatory liabilities	839,360		846,430
Total regulatory liabilities	$	869,396	$	899,084

(1)Recovered (credited) per specific rate orders

(2)IPL receives a return on its discretionary funding

(3)Recovered with a current return

(4) The majority of these costs are being recovered in basic rates and charges through 2026. For the remainder, recovery is probable, but the

timing is not yet determined.

(5) Recovered per regulatory precedent.