20 C.F.R. § 725.494 : Employees' Benefits — OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR — FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, AS AMENDED — CLAIMS FOR BENEFITS UNDER PART C OF TITLE IV OF THE FEDERAL MINE SAFETY AND HEALTH ACT, AS AMENDED — RESPONSIBLE COAL MINE OPERATORS — Potentially liable operators

An operator may be considered a "potentially liable operator" with respect to a claim for benefits under this part if each of the following conditions is met:

(a) The miner's disability or death arose at least in part out of employment in or around a mine or other facility during a period when the mine or facility was operated by such operator, or by a person with respect to which the operator may be considered a successor operator. For purposes of this section, there shall be a rebuttable presumption that the miner's disability or death arose in whole or in part out of his or her employment with such operator. Unless this presumption is rebutted, the responsible operator shall be liable to pay benefits to the claimant on account of the disability or death of the miner in accordance with this part. A miner's pneumoconiosis, or disability or death therefrom, shall be considered to have arisen in whole or in part out of work in or around a mine if such work caused, contributed to or aggravated the progression or advancement of a miner's loss of ability to perform his or her regular coal mine employment or comparable employment.
(b) The operator, or any person with respect to which the operator may be considered a successor operator, was an operator for any period after June 30, 1973.
(c) The miner was employed by the operator, or any person with respect to which the operator may be considered a successor operator, for a cumulative period of not less than one year (§725.101(a)(32) ).
(d) The miner's employment with the operator, or any person with respect to which the operator may be considered a successor operator, included at least one working day (§725.101(a)(32) ) after December 31, 1969.
(e) The operator is capable of assuming its liability for the payment of continuing benefits under this part. An operator will be deemed capable of assuming its liability for a claim if one of the following three conditions is met:
(1) The operator obtained a policy or contract of insurance under section 423 of the Act and part 726 of this subchapter that covers the claim, except that such policy shall not be considered sufficient to establish the operator's capability of assuming liability if the insurance company has been declared insolvent and its obligations for the claim are not otherwise guaranteed;
(2) The operator qualified as a self-insurer under section 423 of the Act and part 726 of this subchapter during the period in which the miner was last employed by the operator, provided that the operator still qualifies as a self-insurer or the security given by the operator pursuant to §726.104(b) is sufficient to secure the payment of benefits in the event the claim is awarded; or
(3) The operator possesses sufficient assets to secure the payment of benefits in the event the claim is awarded in accordance with §725.606.

20 C.F.R. § 725.494