In January, the F.C.C. said it had received 126 applications seeking funding beyond what it could reimburse. Lawmakers had underestimated the costs of shredding Huawei and ZTE equipment, and new equipment and labor costs have risen. The F.C.C. said it could cover only about 40 percent of the expenses.

Some wireless carriers immediately paused their replacement efforts. “Until we have assurance of total project funding, this project will continue to be delayed as we await the necessary funding required to build and pay for the new network equipment,” United Wireless of Dodge City, Kan., wrote in a regulatory filing to the F.C.C. in January.

Huawei declined to comment; ZTE didn’t respond to a request for comment.

In southern Alabama’s Black Belt region, known for its historical cotton plantations and paper mills, complying with rip-and-replace has been a central initiative at Pine Belt Cellular, one of the few wireless carriers for 2,000 homes and businesses in five counties.

The company was founded in 1958 by James Nettles, a country doctor in Arlington who installed phone lines into the homes of patients so they could call him for home visits.

After James Nettles’s son, John Nettles, joined the phone business in 1988, the family expanded into wireless service with federal grants. In 2011, John Nettles took additional F.C.C. subsidies and upgraded Pine Belt’s network to include broadband for fast internet service.