Huffman's guilty plea hearing moved up

US actress Felicity Huffman is expected to plead guilty on May 13 to charges that she took part in a sweeping college admissions cheating scam.

The Desperate Housewives star had been scheduled to enter her plea in Boston federal court on May 21, but a judge on Monday agreed to move up the hearing because the lead prosecutor would be out of town.

Huffman (56) was accused of paying a consultant $US15,000 ($NZ22,000) disguised as a charitable donation to boost her daughter's SAT  (suite of assessments) score.

The SAT is a standardised test widely used for college admissions in the US.

Huffman will plead guilty to conspiracy to commit mail fraud and honest-services mail fraud, according to court documents.

Those charges are punishable by up to 20 years in prison, but the plea agreement indicates prosecutors will seek a sentence of four to 10 months.

Also on Monday, lawyers formally entered not guilty pleas in court on behalf of Full House actress Lori Loughlin, her husband, Mossimo Giannulli and more than a dozen other parents.

They had previously pleaded not guilty in court documents. The judge allowed the parents to skip their arraignment.

Loughlin and Giannulli are charged with paying $US500,000 in bribes to get their daughters into the University of Southern California.